The research project has dual objectives. The first is to identify gustatory, olfactory and oral trigeminal stimuli which influence salivary flow in humans. Whole mouth and parotid salivary secretion rates will be measured after exogenous stimulation. The second research objective is to evaluate the effects of salivary flow on human taste perception by measuring the taste recognition thresholds and suprathreshold taste intensities of subjects receiving medications which alter salivary flow.